Critical Limb Ischemia in a Young Patient With a Mechanical Aortic Valve Leading to Bilateral Above-Knee Amputation.

This case reports a 24-year-old female with prior aortic insufficiency who underwent a mechanical aortic valve replacement with subsequent transient ischemic attacks and documented subtherapeutic international normalized ratio (INR). She presented with pain and bilateral lower extremity pulselessness. Workup showed a supratherapeutic INR, no thrombus on echocardiogram, and computed tomography angiography demonstrating no flow in the bilateral common femoral arteries. Patient failed repeated thrombectomies and had a bilateral above-knee amputation. The patient was suspected to have acute on chronic emboli from the mechanical aortic valve and further testing did not elucidate contributory causes of her critical limb ischemia. We believe this is the first documented case of bilateral lower extremity ischemia due to mechanical valve complications.

Site-specific differences in latency intervals during biventricular pacing: impact on paced QRS morphology and echo-optimized V-V interval.

OBJECTIVE: To investigate differences in latency intervals during right ventricular (RV) pacing and left ventricular (LV) pacing from the (postero-)lateral cardiac vein in cardiac resynchronization therapy (CRT) patients and their relationship to echo-optimized interventricular (V-V) intervals and paced QRS morphology. METHODS: We recorded digital 12-lead electrocardiograms in 40 CRT patients during RV, LV, and biventricular pacing at three output settings. Stimulus-to-earliest QRS deflection (latency) intervals were measured in all leads. Echocardiographic atrioventricular (AV) and V-V optimization was performed using aortic velocity time integrals. RESULTS: Latency intervals were longer during LV (34 ± 17, 29 ± 15, 28 ± 15 ms) versus RV apical pacing (17 ± 8, 15 ± 8, 13 ± 7 ms) for threshold, threshold ×3, and maximal output, respectively (P < 0.001), and shortened with increased stimulus strength (P < 0.05). The echo-optimized V-V interval was 58 ± 31 ms in five of 40 (12%) patients with LV latency ≥ 40 ms compared to 29 ± 20 ms in 35 patients with LV latency < 40 ms (P < 0.01). During simultaneous biventricular pacing, four of five (80%) patients with LV latency ≥ 40 ms exhibited a left bundle branch block (LBBB) pattern in lead V(1) compared to three of 35 (9%) patients with LV latency < 40 ms (P < 0.01). After optimization, all five patients with LV latency ≥ 40 ms registered a dominant R wave in lead V(1) . CONCLUSIONS: LV pacing from the lateral cardiac vein is associated with longer latency intervals than endocardial RV pacing. LV latency causes delayed LV activation and requires V-V interval adjustment to improve hemodynamic response to CRT. Patients with LV latency ≥ 40 ms most often display an LBBB pattern in lead V(1) during simultaneous biventricular pacing, but a right bundle branch block after V-V interval optimization.

Introducing a new entity: chemotherapy-induced arrhythmia.

The relationship between chemotherapy and arrhythmias has not been well established. We reviewed the existing literature to better understand this connection. We reviewed published reports on chemotherapy-induced arrhythmias in English using the PubMed/Medline and OVID databases from 1950 onwards as well as lateral references. Arrhythmias were reported as a side effect of many chemotherapeutic drugs. Anthracyclines are associated with atrial fibrillation (AF) at a rate of 2-10%, but rarely with ventricular tachycardia (VT)/fibrillation. Taxol and other antimicrotubular drugs are safe in terms of pro-arrhythmic side effects and do not cause any consistent rhythm abnormalities. Arrhythmias induced by 5-fluorouracil, including VT, are mostly ischaemic in origin and usually occur in the context of coronary spasm produced by this drug. Cisplatin-particularly with intrapericardial use-is associated with a very high rate of AF (12-32%). Melphalan is associated with AF in 7-12% of cases, but it does not appear to cause VT. Interleukin-2 is linked to frequent arrhythmia, mostly AF. We summarized the available data on chemotherapy-induced arrhythmia, particularly AF and VT. Studies with prospective data collection and thorough analyses are needed to establish a causal relationship between certain anticancer drugs and arrhythmia.

Esophageal contour changes during cryoablation of atrial fibrillation.

BACKGROUND: We have observed contour changes of the barium-filled esophagus during atrial fibrillation (AF) ablation with cryo-energy delivered in direct proximity to the esophagus. OBJECTIVE: To evaluate the frequency, location, and severity of esophageal contour changes during cryo-energy application close to the esophagus. METHODS: We retrospectively analyzed cine-fluoroscopic images acquired during hybrid cryo-radiofrequency AF ablation in 100 consecutive patients with cryo-energy delivered only in direct proximity to the esophagus. RESULTS: Esophageal contour changes were observed in 28 (32%) of 89 patients (and 74 [6.2%] of 1,191 of all cryo applications). They were more frequent in the left common pulmonary vein (PV) (50%) and less so in the right common PV and the upper PVs (4-5%). The distance of the ablation catheter from the endoesophageal contour prior to cryo-energy applications associated with contour changes was 1.8 +/- 1.5 mm, which increased to 4.1 +/- 1.6 mm at the time of peak contour change (P < 0.001). The esophageal contour deformation was 2.3 +/- 0.9 mm. There were no apparent complications related to cryo-energy application for 3-4 minutes, even if associated with contour changes. CONCLUSION: Esophageal contour changes were observed in >6% of cryo applications in direct proximity to the esophagus (32% of patients) and were most frequent in the posterior aspect of the left common and right lower PV ostium when cryo-energy was delivered at a distance of

AV junctional ablation allowing more effective delivery of cardiac resynchronization therapy in patients with intra- and interatrial conduction delay.

We report two patients with cardiac resynchronization therapy (CRT) devices and evidence of refractory heart failure in whom impaired intraatrial conduction in one patient, and interatrial conduction in the other, prohibited optimization of the atrioventricular (AV) timing sequence. The patient with intraatrial conduction delay exhibited late right atrial sensing and latency during right atrial pacing that required programming of a short-sensed AV delay and long-paced AV delay (wide differential AV delay). In both patients AV junctional ablation and echocardiography-guided device optimization significantly improved heart failure.